Locomotives are returned periodically to a service facility for preventative and corrective maintenance. The engine cooling system of a locomotive is an important system that is routinely inspected. The frequency of inspection of a locomotive cooling system may vary from one railroad to another, with annual and condition-based inspections often specified. The inspection is performed by visually checking for leaks while applying hydrostatic pressure to the cooling system with the locomotive engine in a cold shutdown condition; commonly called a “squeeze test.” If a fluid leak is detected, the suspect part is repaired or it is removed and replaced.
Water leaks have been known to occur at a variety of locations in a locomotive, both from engine components and from cooling system components apart from the engine, i.e. piping, valves, pumps, sight glass, etc. Engine components known to leak water include the turbocharger, the intercooler, the fuel heater, and the cylinder assembly (power assembly). While it may be relatively easy to repair or replace some cooling system components, the repair of engine components, particularly engine power assemblies, is a costly and time-consuming matter.